Method for post-molding a molded article conditioning apparatus with a selectively controlled transfer flow structure

ABSTRACT

A cooling tube assembly for operating on a malleable molded plastic part. The cooling tube assembly comprising a porous tube/insert having a profiled inner conditioning surface, and a vacuum structure configured to cooperate with the porous tube. In use, the vacuum develops a reduced pressure adjacent the inner conditioning surface to cause an outer surface of the malleable molded plastic part, locatable within the cooling tube assembly, to contact the inner conditioning surface of the porous insert so as to allow a substantial portion of the outer surface of the malleable part, upon cooling, to attain a profile substantially corresponding to the profile of the inner conditioning surface. The cooling tube assembly further including a suction channel therein that is configured to cooperate with a valve member for the control of a suction flow therethrough that assists in a transferring of the molded article into the cooling tube assembly.

CROSS-REFERENCE TO RELATED PRIOR APPLICATION

This application is a continuation of prior application Ser. No.11/078,769, filed on Mar. 10, 2005 now U.S. No. 7,252,497 and claims thebenefit therefrom.

TECHNICAL FIELD

The present invention relates, in general, to a post-molding moldedarticle conditioning apparatus and is particularly, but not exclusively,applicable to a cooling tube assembly used in a plasticinjection-molding machine to cool plastic parts, such as plasticparisons or preforms. More particularly, the present invention relatesto a structural configuration of the cooling tube assembly, and also tomethod of manufacturing and using such devices, for example in thecontext of a manufacturing process for preforms made from polyethyleneterephthalate (PET) or the like.

BACKGROUND OF THE INVENTION

In order to improve the efficiency of a molding system, or to enhancethe qualities of the molded articles produced therein, molding systemshave evolved to include a myriad varieties of post-molding moldedarticle conditioning systems. Of these conditioning systems, most areconfigured to simply alleviate in-mold cooling time, and hence operateto reduce the overall duration of the molding cycle. However, it is alsoknown to configure and use post-molding molded article conditioningsystems to enhance the characteristics of the molded article (e.g.impart localized crystallinity in the plastic structure; impart atemperature profile to the molded article that is suitable for asubsequent molding process; reshaping of a portion of the moldedarticle; removing of unwanted features such as gate vestige; etc.).

As an example, and without specific limitation, a typical injectionmolding system 2 that includes a post-molding molded articleconditioning system is shown with reference to FIG. 1. The injectionmolding system 2 is configured for the production of plastic preforms 32(or parisons) that are used in the blow molding of bottles. As a furtherexample, the injection molding system could be an INDEX (Trademark ofHusky Injection Molding Systems Ltd.) molding system such as thatdescribed in U.S. Pat. No. 6,113,834 to Kozai et al., issued Sep. 5,2000.

Referring back to FIG. 1, the injection-molding system 2 comprisesmolding structure that includes, without specific limitation, a clampunit 4 with an injection mold arranged therein, an injection unit 6, anda robot 8 with an end-of-arm-tool (EOAT) 11 arranged thereon. Theinjection mold comprises complementary mold halves 12, 14, with one ormore preform mold cavities configured therein. Each mold cavity isconfigured in a stack of cooperating molding inserts that include a core22 and a cavity 24, that are disposed on the mold halves 12, 14. Theinjection mold halves 12, 14, (shown in an open configuration in FIG. 1)are mounted between a fixed and a movable platen 16, 18 of the clamp 4.A set of tie bars 20 connect the platens 16, 18 with a clamp mechanism21. The EOAT 11 comprises a take-out plate 28 with a one or more preformcooling tube assemblies 30 arranged on a surface thereof. The number ofcooling tube assemblies 30 on the surface of the take-out plate 28 isequal to, or a multiple of, the number of mold cavities configured inthe mold.

The EOAT 11 may be advantageously configured to include the cooling tubeassembly 30 that is described in commonly assigned U.S. Pat. No.6,737,007 to Neter et al., issued May 18, 2004, or the similarlyconfigured cooling tube assembly described in commonly assigned PCTpatent application WO 03/086,728 to Pesavento, published Oct. 23, 2003.In particular, the cooling tube assembly 30 is configured for apost-molding conditioning of at least a portion of a malleable injectionmolded perform received therein. The cooling tube assembly 30 includes aconditioning body (not shown) with a conditioning cavity that isconfigured therein along a cooled inner conditioning surface. Theconditioning cavity is configured to sealingly receive, and thereaftercondition, the portion of the preform by expanding at least a portion ofan outer surface thereof into contact with the cooled inner conditioningsurface. Accordingly, the conditioning body is configured for connectionwith a heat dissipation path (not shown) and an air pressure structure,via the take-out plate 28, to perform the preform conditioning as willbe explained in further detail hereinafter. The air pressure structuremay be selectably configured to be connected to a vacuum pump 34 or asource of compressed air (not shown). In more detail, the conditioningbody is configured to include a porous insert (not shown) that is formedfrom a thermally conductive porous material, such as porous aluminum.The porous insert is configured to include a porous inner conditioningsurface configured therein that provides at least a portion of the innerconditioning surface of the conditioning cavity. The porous insert isfurther configured to connect the inner porous surface thereon with theheat dissipation path and the air pressure structure to perform theconditioning of the preform portion.

An injection molding process cycle for the production of one or morepreforms begins with the step of closing of the mold by moving of themovable platen 18 relative to the fixed platen 16 by means of strokecylinders (not shown), or the like, to close the mold. A mold clampingforce is then applied to the mold halves 12, 14 by the clamp mechanism21. Next, the injection unit fills and pressurizes the mold cavities anda corresponding number of preforms are formed. The mold is then openedonce the molded preforms have been partially cooled in the mold to anextent required to avoid significant deformation thereof during asubsequent step of ejection. The robot 8 then positions theend-of-arm-tool (EOAT) 11 between the mold halves 12, 14 to align thecooling tube assemblies 30 with the one or more preforms that areretained on their cores 22. The preforms are then ejected from the moldcores 22, by an actuation of a mold stripper plate 33, and the preformsare transferred into the cooling tube assemblies 30. The robot 8 thenwithdraws the EOAT 11 from between the mold halves 12, 14 and themolding cycle can repeat.

Contemporaneously to the molding of a subsequent shot of preforms 32, apost-molding conditioning process is performed in the cooling tubeassemblies 30 that begins with the step of transferring the partiallycooled, and hence malleable, preforms 32 from the mold cores 22 into thecooling tube assemblies 30. The foregoing transfer is generally assistedby a suction flow of air that is established along the innerconditioning surface of the conditioning cavity to a suction channel(not shown) that is configured in an end portion in the conditioningbody and that is connected with the air pressure structure. Once atleast a portion of the preforms 32 are sealingly received in the coolingtube assemblies 30, an outer surface of the each preform portion isexpanded into contact with the cooled inner conditioning surface of therespective conditioning cavity. The foregoing is accomplished byevacuating any air contained between the outer surface of the preform 32and the inner conditioning surface of the conditioning body through theporous inner conditioning surface of the porous insert under an appliedvacuum provided by the air pressure structure/vacuum pump 34.Thereafter, the outer surface of the preform 32 is kept in contact withthe cooled inner conditioning surface of the conditioning body, bymaintaining the vacuum, until the preform 32 has been solidified to anextent required to maintain its shape once ejected from the cooling tubeassembly. Thereafter, the preforms 32 are ejected from their respectivecooling tube assemblies 30 by connecting the air pressure structure tothe source of compressed air and pressurizing of the conditioning cavityby blowing air through the porous inner conditioning surface of theporous insert and also possibly through the pressure channel.

It is the ability of the cooling tube assembly 30 to expand, and tomaintain, any desired portion of the outer surface of a preform 32 in anintimate contact with the cooled inner conditioning surface thereof thatprovides for significant advantage. In particular, the intimate contactprovides for optimal conductive heat transfer efficiency therebetween,while also assuring a homogenous cooling of the outer surface of thepreform that avoids certain types of defects (e.g. banana shapedpreforms, ovality, gate vestige stretching, gate vestige crystallinity,etc.). Moreover, it is also possible to configure the cooled innerconditioning surface of the cooling tube assembly 30 to perform a shapecorrection of the preform (i.e. substantially prevent preform shapevariations that are commonly caused by variations in the moldingprocess, post-molding cooling, shrinkage, etc.) or to significantlyre-shape the preform as desired (e.g. for the purposes of preferentialblow molding as described in detail in WO 03/086,728, as introducedhereinbefore.

Despite the significant improvements that are available through the useof the various known molded article conditioning apparatus, and inparticular the cooling tube assembly 30 described hereinbefore, theredoes however remain areas for further improving the structure andoperation thereof.

For instance, while it is desirable to provide the cooling tube assembly30 with a suction channel, as previously described, for assisting in thetransfer of the preform 32 from the mold core 22 thereto, a continuedapplication of vacuum pressure therethrough during the step of preformexpansion and cooling can be the cause certain defects in the preform32. In particular, a gate vestige 80A located on an end portion 80 ofthe preform 32, as shown with reference to FIG. 3B, can be significantlydeformed as it is being sucked down the suction channel. Accordingly, itis desired to configure an improved cooling tube assembly that includesa means for controlling the suction flow through the suction channelwhereby the suction channel remains connected to the air pressurestructure only during the step of preform transfer.

Similarly, it is desired to configure the porous insert with an improvedstructure for connecting the air pressure structure with the innerporous surface disposed thereon.

Likewise, it is desired to configure a porous insert with a simplifiedcooling configuration.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, a method isprovided for molding an article in a molding system that includes amolding machine and a post-molding molded article conditioningapparatus. The method includes the steps of molding a molded article,configuring a pressure structure connected to said conditioningapparatus to function as a vacuum source, moving a valve member of saidconditioning apparatus into an open configuration to connect aconditioning cavity of said conditioning apparatus to said vacuum sourcethrough a transfer flow structure of said conditioning apparatus,transferring said molded article, in a malleable state, into saidconditioning cavity with the assistance of suction provided through saidtransfer flow structure, moving said valve member into a closedconfiguration once a portion of said molded article has been sealinglyreceived within said conditioning cavity, expanding an outer surface ofsaid portion of said molded article into contact with a cooled innerconditioning surface of said conditioning cavity by evacuating any aircontained between said outer surface of said molded article and saidcooled inner conditioning surface through a plurality of openingsconfigured along at least a portion of said cooled inner conditioningsurface and through to said pressure structure via a pressure couplingstructure of said conditioning apparatus, maintaining a vacuum to holdsaid outer surface of said preform in contact with said cooled innerconditioning surface of said conditioning cavity until said moldedarticle has solidified to an extent required to maintain its shape onceejected from said conditioning apparatus, ejecting said molded articlefrom said conditioning cavity.

The valve member is preferably configured to include a top surface forsupporting an adjacent portion of the outer surface of the moldedarticle.

The conditioning apparatus is preferably configured to include a porousinsert formed from a first porous material and wherein at least aportion of said inner conditioning surface is disposed thereon. Theporous insert including the plurality of flow channels therein as anetwork of interconnected interstitial spaces.

In an alternative embodiment of the present invention the conditioningapparatus may be configured to include a porous member that isconfigured with the first porous material providing an inner porousportion that is at least partially enclosed, on an outer surfacethereof, by an outer porous portion formed from a second porousmaterial, the second porous material having a network of interconnectedinterstitial spaces that function as the pressure coupling structure.

In accordance with yet another embodiment of the invention, the porousmember includes at least one cooling channel configured thereon, andwherein a surface of the cooling channel includes a surface treatmenttherealong for a substantial sealing thereof to avoid leakage of acoolant to be circulated therethrough. Preferably, the cooling channelis configured on an outer surface of said porous member, and wherein anouter surface of the porous member has been configured to include thesurface treatment, and the outer surface being further configured toreceive a sleeve for enclosing the at least one cooling channel.

BRIEF DESCRIPTION OF THE FIGURES

Exemplary embodiments of the present invention will now be describedwith reference to the accompanying Figures, in which:

FIG. 1 is a plan view of a typical injection molding machine includingan injection unit, clamp unit, robot, mold, and end-of-arm tool;

FIG. 2 depicts an exploded isometric view of a cooling tube assemblyaccording to an embodiment of the present invention;

FIG. 3A depicts a sectional view of the cooling tube assembly of FIG. 2,taken along the line A-A, that is arranged on a take-out plate (shown inpartial section), with a suction channel valve member being arranged ina closed configuration as a porous inner conditioning surface of aconditioning cavity is undergoing a post-ejection cleaning purge;

FIG. 3B depicts the section view of the cooling tube assembly of FIG.3A, with the suction channel valve member being arranged in an openconfiguration to configure a suction flow as a malleable preform isshown partially received in the conditioning cavity;

FIG. 3C depicts the section view of the cooling tube assembly of FIG.3A, with the suction channel valve member being arranged in a closedconfiguration as a malleable preform is being cooled with an outersurface thereon having been expanded into contact with the porous innerconditioning surface of the conditioning cavity;

FIG. 3D depicts an isometric view of a valve member in accordance withan embodiment of the present invention;

FIG. 4A depicts a section view of a cooling tube assembly according to afirst alternative embodiment of the present invention that includes analternative configuration of the suction channel and valve member;

FIG. 4B depicts a section view of a cooling tube assembly according to asecond alternative embodiment of the present invention that includes analternative configuration of the suction channel and valve member;

FIG. 5A depicts a section view of a cooling tube assembly according to athird alternative embodiment of the present invention that includes analternative configuration of the suction channel and valve member, thevalve member being arranged in an open configuration to configure asuction flow as a malleable preform is shown partially received in theconditioning cavity;

FIG. 5B depicts the section view of the cooling tube assembly of FIG.5A, with the suction channel valve member being arranged in a closedconfiguration as a malleable preform is being cooled with an outersurface thereon having been expanded into contact with the porous innerconditioning surface of the conditioning cavity;

FIG. 5C depicts the section view of the cooling tube assembly of FIG.5A, with the suction channel valve member being arranged in an extendedconfiguration to assist in an ejection of the solidified preform;

FIG. 6 depicts a section view of a cooling tube assembly according to afourth alternative embodiment of the present invention that includes analternative configuration of a porous insert that comprises an innerporous portion formed from a first porous material that is at leastpartially enclosed, on an outer surface thereof, by an outer porousportion formed from a second porous material, the outer porous portionbeing configured with a higher porosity to provide a suitable means forconnecting the inner porous portion with an air pressure structure (notshown);

FIG. 7 depicts a section view of a cooling tube assembly according to afifth alternative embodiment of the present invention that includes avariant to the porous insert of FIG. 6, wherein the inner porous insertis configured to provide a complete conditioning cavity;

FIG. 8A depicts a section view of a cooling tube assembly according to asixth alternative embodiment of the present invention that includes avariant to the porous insert of FIG. 7, wherein a network of cooling theinner porous insert is configured on an outer surface thereof thatinclude a surface treatment for a substantial sealing thereof;

FIG. 8B depicts a side view of the cooling tube assembly of FIG. 8Ashowing the configuration of the network of cooling channels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

With reference to FIG. 2, a cooling tube assembly 50 in accordance withan embodiment of the present invention is shown. The cooling tubeassembly 50 is configured for use with an end-of arm-tool 11 in aninjection molding system 2 for a post-molding conditioning of at least aportion of a malleable injection molded preform 32. The cooling tubeassembly 50 includes a valve member 70, a base insert 55, a cooling tube54, a porous insert 52, and a sleeve 56.

The construction and use of the embodiment of the cooling tube assembly50 will be described with reference to FIGS. 3A, 3B, 3C and 3D.

The base insert 55 comprises a substantially cylindrical body. An innerconditioning surface 61B is configured in the cylindrical body thatpreferably reflects a shape of an outer surface of an end portion 80 ofthe preform 32. The inner conditioning surface 61B includes a gatevestige portion 61C that is again preferably configured to receive agate vestige 80A that is centrally located at a distal end of thepreform 32. An outer cylindrical surface of the cylindrical body isconfigured to arrange the base insert 55 in a complementary shaped firstbore that is configured through a bottom surface of the cooling tube 54.An inlet and an outlet cooling channel 95 are configured in thecylindrical body between a bottom surface thereof, for connection withcoolant inlet and outlet ports 116 provided on a carrier plate 28 of theend-of-arm-tool 11, and the outer cylindrical surface, for connectionwith an inlet and an outlet coolant connecting channel 98 configured inthe cooling tube. A connecting pressure channel 97 is configured in thecylindrical member between the bottom surface, for connection with apressure port 120 provided on the carrier plate 28, and the outercylindrical surface substantially adjacent an annular pressure channel99. The annular pressure channel 99 is configured between a top surfaceof the base insert 55, a top surface of the first bore in the coolingtube 54, and the outer surface of the porous insert 52. A suctionchannel 96 is also configured in the cylindrical body, along thelongitudinal axis thereof, between the bottom surface and through thegate vestige portion of the end surface 61C.

In more detail, the suction channel 96 preferably includes the followingportions, listed from top to bottom. An orifice that is configured atthe interface between the suction channel 96 and the inner conditioningsurface 61C. A cylindrical spigot portion 73 that is configured toreceive a complementary cylindrical spigot portion 73′ of the valvemember 70. A tapered sealing portion 74 that is configured to cooperatewith a complementary sealing portion 74′ provided on the valve member70, when the valve member is in a closed configuration. A cylindricalportion 76 that is configured to function as a valve cylinder for areciprocation of the valve member 70 therein, between the closed and anopen configuration. A distal end of the suction channel 96 beingconfigured for connection with a suction pressure port 122 of thecarrier plate 28.

The porous insert 52 comprises a tubular body preferably formed from athermally conductive first porous material. A porous inner conditioningsurface 61A is configured on the tubular body that preferably reflects ashape of an outer surface of a body portion 80 of the preform 32. Anouter cylindrical surface 64 of the tubular body being configured toarrange the porous insert 52 in a complementary shaped second boreprovided in the cooling tube 54 such that the bottom surface of the baseinsert 55 is arranged adjacent the top surface of the porous insert. Anetwork of pressure distribution channels 66 are configured along anouter surface 64 of the porous insert, best shown with reference to FIG.2, and that extend from the bottom surface thereof for connection withthe annular pressure channel 99. In addition, a network ofinterconnected interstitial spaces in the first porous material of thetubular body provide a plurality of flow channels that fluidly connectthe porous inner conditioning surface 61A with the network ofdistribution channels 66.

The first porous material preferably comprises a sintered matrix ofpowder particles, of a thermally conductive material, having apredominant size in the range of 5 μm to 40 μm to produce resultinginterstitial spaces of a size and shape that substantially avoidsimparting a noticeable change in a finish of the outer surface of thepreform 32. More preferably, the predominant size of said particle is inthe range of 8 μm to 20 μm. More preferably still, the predominantparticle size is about 12 μm. Accordingly, the presently preferredporosity (i.e. size of the interstitial spaces) along the inner porousconditioning surface is about 12 μm.

The presently preferred thermally conductive material is bronzeparticles. However, other suitable metals could be used, such asaluminum. In addition, it may also be possible to use thermallyconductive ceramics such as silicon carbide and a tungsten carbide.

The cooling tube 54 comprises a substantially tubular body preferablymade from a thermally conductive material. The tubular body includingthe first bore, longitudinally extending along a bottom portion thereof,that is configured for receiving the base insert 55. The second bore,configured for receiving the porous insert 52, is configured tolongitudinally extend along an upper portion thereof. The inlet and anoutlet coolant connecting channels 98 are configured between an innersurface of the first bore and ends of a cooling channel 58 that isconfigured in an outer surface of the cooling tube 54. The outer surfaceof the cooling tube 54 is further configured to cooperate with an innersurface of the sleeve 56 to sealingly enclose the cooling channel 58.Preferably, a groove configured in a top surface of the cooling tube 54,adjacent the porous insert 52, is configured to receive an end seal 104for cooperating with a bottom surface of a preform support ledge portion86 for sealingly enclosing a portion of the outer surface of the preform32 within the cooling tube assembly 50. A bottom portion of the coolingtube 54 is configured to include a flange 93 for arranging and retainingthe cooling tube assembly 50 on the carrier plate 28.

The seal member 104 is preferably shaped to include an inwardlyprojecting lip to assist in its retention in the groove provided on thetube body 54. Preferably the seal member 104 is made from alow-durometer silicone, preferably with a durometer value of about 50,to avoid deforming the bottom surface of the preform support ledge 86.

The sleeve 56 comprises a substantially tubular body with the innercylindrical surface for enclosing the coolant channel on the outside ofthe cooling tube 54 as described hereinbefore.

The valve member 70 comprises a substantially cylindrical body. Thevalve member 70 preferably includes the following portions, listed fromtop to bottom. A gate vestige support face 72 arranged on a top surfaceof a cylindrical spigot portion 71. The support surface 72 beingconfigured to support a bottom face of the preform gate vestige 80A whenthe valve member 70 is arranged in the closed configuration. An outersurface 73′ of the cylindrical spigot portion 71 is configured tocooperate with the cylindrical spigot portion 73 of the suction channel96 to assist in positioning the gate vestige support face 72 adjacentthe gate vestige portion 61C. The complementary tapered sealing face 74′is configured as an outwardly tapering face for cooperating with thesuction channel sealing face 74 for the selective closing of the suctionchannel (i.e. isolating the suction channel orifice from the airpressure structure). A complementary cylindrical portion 76′ of theouter surface of the cylindrical body is configured for cooperation withthe cylindrical portion 76 of the suction channel 96 for supporting analigned reciprocation of the valve member 70 therein. The valve member70 also includes a set of four shallow, equi-spaced, longitudinallyaligned, bypass pressure channels 75 that are configured through theouter surface of the cylindrical body around the periphery of thecomplementary cylindrical portion 76′. The bypass pressure channels 75each include a first opening on the tapered sealing portion 74′, and asecond opening on a bottom face of the cylindrical body. The firstopening being exposed when the valve member 70 is arranged in the openconfiguration and is obstructed by the tapered sealing portion of thesuction channel 96 when the valve member is arranged in the closedconfiguration. Accordingly, the bypass pressure channels 75 provide afluid connection along the cylindrical body when the valve member is inthe open configuration. A cylindrical spring seat portion beingconfigured around an end portion of the cylindrical body between aradial relief 78 and an upper shoulder 77. The spring seat portion isconfigured to retain a first end portion of a spring 102 that biases thevalve member 70 into the closed configuration. A second end portion ofthe spring 102 is preferably arranged on a shoulder 132 provided at thebase of a bore 130 that is configured along an upper portion of thesuction pressure port 122 in the carrier plate 28.

Preferably, a pressure port valve 90 may be configured in the carrierplate 28 adjacent each cooling tube assembly 50 that is configured forselectively opening or closing the air pressure structure that connectstherewith. Accordingly, one or more cooling tube assemblies 50 of amulti-tube array can be selectively disconnected. This is particularlyadvantageous feature in case of a molding system 2 fault that shuts downone or more molding cavities.

A method for molding a preform 32 in an injection molding system 2, asshown with reference to FIG. 1 and further including the cooling tubeassembly 50 of the present invention, involves the known steps ofmolding and conditioning that were described hereinbefore and with theadditional steps of operating the suction channel valve member 70. Inparticular, prior to the commencement, or during midst, of the step oftransferring the malleable preforms 32 from the mold cores 22 into thecooling tube assemblies 50, an additional step of moving of the suctionvalve member 70 into the open configuration is performed. In so doing, asuction flow is established through the suction channel 96, as generallyindicated by the air flow lines at symbol ‘B’ with reference to FIG. 3B.Once the preform 32 is substantially received in the conditioning cavityof the cooling tube assembly 50, an additional step of moving of thesuction valve member 70 into the closed configuration is performed. Inso doing, the suction channel 96 is closed, and a bottom surface of thepreform gate vestige 80A is preferably supported by the support surface72 of the valve member 70. The known process of conditioning the preformcan then be followed, including the first effective step of preformconditioning wherein the outer surface of the preform 32 is expandedinto contact with the cooled inner conditioning surface of the coolingtube assembly 50 by air evacuation, as generally indicated by the airflow lines at symbol ‘C’ with reference to FIG. 3C. Thereafter, thesecond effective step of conditioning is performed wherein the preform32 is cooled in a sustained contact with the inner conditioning surfaceof the cooling tube assembly 50. Once fully conditioned, the preform 32may be ejected from the cooling tube assembly 50. Preferably, the stepof ejection may be performed by configuring the air pressure source toprovide a positive air pressure wherein an outward flow through theporous inner conditioning surface 61A of the cooling tube assembly 50 isestablished, as generally indicated by the air flow lines at symbol ‘A’with reference to FIG. 3A, a pressurization of the conditioning cavitypropels the preform 32 therefrom.

As an example, for sake of operating an EOAT 11 with twenty-four coolingtube assemblies 50 arranged thereon, a vacuum pressure of between 61 and71 centimeters of Mercury (24-28″ Hg) is preferred.

With reference to FIG. 4A, a cooling tube assembly 150 in accordancewith a first alternative embodiment of the present invention is shown.The cooling tube assembly 150 is configured substantially the same asthe embodiment of the invention, and as shown with reference to FIGS. 2and 3A and as previously described, the differences being in theconfiguration of the suction channel 196 and the valve member 170.Accordingly, only the differences in structure and operation will bedescribed.

The suction channel 196 is preferably configured to include thefollowing portions, listed from top to bottom. An orifice that isconfigured at the interface between the suction channel 196 and theinner conditioning surface 61C. A spherical sealing portion 174 that isconfigured to cooperate with a complementary spherical outer surface174′ provided on a ball valve member 170, when the valve member is in aclosed configuration. A cylindrical portion 176 that is configured toprovide a passageway for a reciprocation of the ball valve member 170therein, between the closed and an open configuration. The cylindricalportion 176 being configured to be wider than the diameter of the ballvalve member 170 whereby an annular pressure bypass channel 175 isconfigured therebetween that functions to provide a fluid connectionalong the length of the ball valve member in the open configuration. Adistal end of the suction channel 96 being configured for connectionwith a suction pressure port 122 of the carrier plate 28.

With reference to FIG. 4B, a cooling tube assembly 250 in accordancewith a second alternative embodiment of the present invention is shown.The cooling tube assembly 250 is configured substantially the same asthe embodiment of the invention, and as shown with reference to FIGS. 2and 3A and as previously described, the differences being in theconfiguration of the suction channel 296 and the valve member 270.Accordingly, only the differences in structure and operation will bedescribed.

The suction channel 296 is preferably configured to include thefollowing portions, listed from top to bottom. An orifice that isconfigured at the interface between the suction channel 296 and theinner conditioning surface 61C. A conical bore 276 that includes asealing portion 274 at the top thereof that is configured to cooperatewith a complementary conical outer surface 274′ provided on afrustoconical valve member 270, when the valve member is in a closedconfiguration. The conical bore 276 being configured to be longer thanthe valve member 276 to allow for a reciprocation of the valve member270 therein, between the closed and an open configuration. An annularpressure bypass channel (not shown) is configured between the outersurface of the valve member 270 and the inner surface of the conicalbore 296 to provide a fluid connection along the length of the valvemember 270 in the open configuration. A distal end of the suctionchannel 296 being configured for connection with a suction pressure port122 of the carrier plate 28.

With reference to FIGS. 5A, 5B, 5C, a cooling tube assembly 350 inaccordance with a third alternative embodiment of the present inventionis shown. The cooling tube assembly 350 is configured substantially thesame as the embodiment of the invention, and as shown with reference toFIGS. 2 and 3A and as previously described, the differences being in theconfiguration of the suction channel 396 and the valve member 370.Accordingly, only the differences in structure and operation will bedescribed.

The suction channel 396 preferably includes the following portions,listed from top to bottom. An orifice that is configured at theinterface between the suction channel 396 and the inner conditioningsurface 61C. A cylindrical sealing portion 374 that is configured toreceive a complementary cylindrical sealing portion 374′ configuredaround a distal tip of a slender cylindrical valve member 370. Acylindrical bore 376, with an arbitrarily shaped spherical end portion373, that provides an annular pressure bypass channel (not shown)between an inner surface thereof and the outer surface of the valvemember 370 to provide a fluid connection along the length of the valvemember 270 in the open configuration. A distal end of the suctionchannel 296 being configured for connection with a suction pressure port122 of the carrier plate 28.

Preferably, the valve member 370 is operated by a compound pistonassembly 380 that is arranged in an end-of-arm-tool plate assembly 328,329. The structure and operation of the piston assembly 380 is generallydescribed with reference to commonly assigned U.S. Pat. RE 38,480,issued Mar. 30, 2004. In brief, the compound piston assembly 380includes a first piston 384 arranged in first piston bore configured ina valve bushing 382, and a second piston 386 arranged in a second pistonbore configured in the first piston 384. The valve member 370 includes ahead 377 at an end thereof for connection with the second piston 386.The valve bushing 382 is arranged in a seat configured between a carrierplate 328, a valve plate 329, and a air manifold 327. The air manifold327 connects the compound piston assembly 380 with air channels providedtherein that can be pressurized in a sequence for positioning the valvemember between an open, closed, or extended positions, as shown withreference to FIGS. 5A, 5B, & 5C, respectively. The extended positionprovides an added measure to ensure the ejection of the preform 32 afterit has been fully conditioned as explained hereinbefore.

With reference to FIG. 6, a cooling tube assembly 450 in accordance witha fourth alternative embodiment of the present invention is shown. Thecooling tube assembly 450 is configured substantially the same as theembodiment of the invention, and as shown with reference to FIGS. 2 and3A and as previously described, the differences being in theconfiguration of the porous insert 452. Accordingly, only thedifferences in structure and operation will be described.

The porous insert 452 comprises a tubular body with an inner portion452B preferably formed from a thermally conductive first porous materialthat is at least partially enclosed, on an outer surface thereof, by anouter porous portion 452A preferably formed from a second porousmaterial. A porous inner conditioning surface 61A is configured theinner porous portion 452B that preferably reflects a shape of an outersurface of a body portion 80 of the preform 32. A network ofinterconnected interstitial spaces in the second porous portion 452Aprovide a pressure distribution structure that provides a fluidconnection between the annular pressure channel 99 and the inner porousportion 452A. Similarly, a network of interconnected interstitial spacesin the first porous portion 452A provides a further connection to theinner porous surface 61A thereon. As before, an outer surface of theporous insert 452 is configured to be received in the second bore of thecooling tube 54.

The first porous material preferably comprises a sintered matrix ofpowder particles, of a thermally conductive material, having apredominant size in the range of 5 μm to 40 μm to produce resultinginterstitial spaces of a size and shape that substantially avoidsimparting a noticeable change in a finish of the outer surface of thepreform 32. More preferably, the predominant size of said particle is inthe range of 8 μm to 20 μm. More preferably still, the predominantparticle size is chosen to be about 12 μm.

The second porous material preferably comprises a sintered matrix ofpowder particles, of a thermally conductive material, having apredominant size in the range of 20 μm to 100 μm to provide a relativelylow pressure drop across the outer porous portion 452A for providing afast and homogenous pressure response across the inner porous portion452B. More preferably, the predominant size of said particle is in therange of 40 μm to 60 μm. More preferably still, the predominant particlesize is chosen to be about 40 μm.

The first and second thermally conductive materials are preferablybronze particles. However, other suitable metals, and for processes fortheir configuration could be used. For example, the porous materialscould be composed of a porous aluminum, such as commercially availableMETAPOR and PORCERAX (both trademarked materials from International MoldSteel Corporation). In addition, it may also be possible to usethermally conductive ceramics such as silicon carbide and a tungstencarbide.

With reference to FIG. 7, a cooling tube assembly 550 in accordance witha fifth alternative embodiment of the present invention is shown. Thecooling tube assembly 550 is configured substantially the same as thefourth alternative embodiment of the invention, and as shown withreference to FIG. 6 and as previously described, the differences beingin the configuration of the porous insert 552 and the obviation of thebase insert 55. Accordingly, only the differences in structure andoperation will be described.

The porous insert 552 comprises a cylindrical body with an inner portion552B formed from a thermally conductive first porous material that is atleast partially enclosed, on an outer surface thereof, by an outerporous portion 552A formed from a second porous material. A porous innerconditioning surface 61A, 61B, 61C is configured along the inner porousportion 552B that preferably reflects a shape of an outer surface of thebody, end, and gate vestige portions 80, 80A, 82 of the preform (preformportions shown with reference to FIG. 3A).

A connecting pressure channel 597 is configured in the inner porousportion 552B between a bottom surface thereof, for connection with apressure port 120 provided on the carrier plate 28, and the outer porousportion 552A. A network of interconnected interstitial spaces in thesecond porous portion 552A provide a pressure distribution structurethat fluidly connects the connecting pressure channel 597 with the innerporous portion 552B. Similarly, a network of interconnected interstitialspaces in the first porous portion 552A provides a further connection tothe inner porous surface 61A, 61B, 61C thereon. An outer surface of theporous insert 552 is configured to be received in a complementary borethat is configured in the cooling tube 554.

Also configured in the porous insert 552 is a suction channel 596 thatis centrally located therein, and that extends longitudinallytherethrough, from the bottom surface and through the bottom of the gatevestige inner conditioning surface portion 61C. The suction channel 596is preferably configured to include the following portions, listed fromtop to bottom. An orifice that is configured at the interface betweenthe suction channel 596 and the inner conditioning surface 61C. Aspherical sealing portion 574 that is configured to cooperate with acomplementary spherical outer surface 174′ provided on a ball valvemember 170, when the valve member is in a closed configuration. Acylindrical portion 576 that is configured to provide a passageway for areciprocation of the ball valve member 170 therein, between the closedand an open configuration. The cylindrical portion 576 being configuredto be wider than the diameter of the ball valve member 170 whereby anannular pressure bypass channel (not shown) is configured betweentherebetween that functions to provide a fluid connection along thelength of the ball valve member in the open configuration. A distal endof the suction channel 596 being configured for connection with asuction pressure port 122 of the carrier plate 28.

The cooling tube 554 comprises a substantially tubular body. The tubularbody including the first bore, longitudinally extending therethrough,that is configured for receiving the porous insert 552. An inlet and anoutlet cooling channel 598 are configured in the tubular body thatextend between a bottom face, for connection with coolant inlet andoutlet ports 116 provided on a carrier plate 28 of said end-of-arm-tool11, and ends of a cooling channel 558 configured in an outer surface ofthe cooling tube. The outer surface of the cooling tube 554 is furtherconfigured to cooperate with an inner surface of the sleeve 56 tosealingly enclose the cooling channel 558. Preferably, a groove isconfigured in a top surface of the cooling tube 554, adjacent the porousinsert 552, for retaining an end seal 104 as previously described. Abottom portion of the cooling tube 554 is configured to include a flange593 for arranging and retaining the cooling tube assembly 550 on thecarrier plate 28.

With reference to FIGS. 8A and 8B, a simplified cooling tube assembly650 in accordance with a sixth alternative embodiment of the presentinvention is shown. The cooling tube assembly 650 includes a porousinsert 652, a sleeve 656, and a valve member 670.

The porous insert 652 comprises a cylindrical body with an inner portion652B formed from a thermally conductive first porous material that is atleast partially enclosed, on an outer surface thereof, by an outerporous portion 652A formed from a second porous material. A porous innerconditioning surface 61A, 61B, 61C is configured along the inner porousportion 652B that preferably reflects a shape of an outer surface of thebody, end, and gate vestige portions 80, 80A, 82 of the preform (preformportions shown with reference to FIG. 3A).

A suction channel 696 is configured in the porous member 652 that iscentrally located therein and that extends longitudinally therethroughfrom the bottom surface and through the bottom of the gate vestige innerconditioning surface portion 61C. The suction channel 696 is preferablyconfigured to include the following portions, listed from top to bottom.An orifice that is configured at the interface between the suctionchannel 696 and the inner conditioning surface 61C. A tapered sealingportion 674 that is configured to cooperate with a complementary sealingportion 674′ provided on the valve member 670, when the valve member 670is in a closed configuration. A cylindrical portion 676 that isconfigured to function as a valve cylinder for a reciprocation of thevalve member 670 therein, between the closed and an open configuration.A distal end of the suction channel 696 being configured to receive aplug 695. A connecting pressure channel 697 being configured between anouter surface of the porous member and the suction channel 696 forconnection with a suction pressure port 120 of the carrier plate 628,via a connecting channel 666 that is configured through the sleeve 656.A network of interconnected interstitial spaces in the second porousportion 652A provide a pressure distribution structure that fluidlyconnects the suction channel 696 with the inner porous portion 652B.Similarly, a network of interconnected interstitial spaces in the firstporous portion 652A provides a further connection to the inner poroussurface 61A, 61B, 61C thereon.

Preferably, a plurality of longitudinally directed coolant grooves 658are configured in an outer surface of the porous insert 652 that extendbetween a pair of semi-circular coolant collector channels 660, 661 thatare also configured in the outer surface of the porous insert 652 inproximity to the ends thereof for interconnecting the coolant groovesinto contiguous coolant circuit. A surface treatment is provided alongthe outer surface of the porous insert 652, coolant grooves 658 and thecollector grooves 660, 661 for a sealing thereof whereby the surfacesthereof are rendered substantially impervious to a leakage of a coolantmedia therethrough. The outer surface of the porous insert 652 isfurther configured to cooperate with an inner surface of the sleeve 656to sealingly enclose the cooling circuit. The ends of the coolantcircuit are configured to be connected to coolant inlet and outlet ports116 provided on a carrier plate 628 of the end-of-arm-tool 11 via a pairof coolant connecting channels 663, 665 that are configured through thesleeve 656.

Preferably, the surface treatment is a chrome plating. Of course, othersuitable surface treatments are possible such as other metal coatings, apolymeric coating, or a ceramic coating.

The sleeve 656 comprises a tubular body, the inner cylindrical surfaceof which is configured for receiving the porous insert 652 as describedhereinbefore. A spigot portion 667 is configured along a lower portionof an outer surface of the sleeve 656. The spigot 667 is configured tocooperate with a complementary bore provided in the carrier plate 628for arranging and retaining the cooling tube assembly 650 therein.Accordingly, the coolant and pressure connecting channels 663, 665, 666are configured between the outer and inner surfaces of the sleeve 656within the spigot portion 667.

The porous inserts of the present invention 52, 452, 552, 652 arepreferably formed using the known method of gravity or “loose powder”sintering. In this method, a powder of a diffusion-bondable material(preferably bronze particles), graded for size, is poured into a moldcavity, which is a void in the shape of the finished part. These metalparticles are then heated to their sintering temperature at which pointa metallurgical bonding takes place, and joining “necks” are formed atcontact points. Preferably, the mold is configured to have a core and acavity portion (not shown), and that the core portion is shaped tocorrespond to the desired final shape of the molded article. If a highlytoleranced shaped surface is required, then a post-sintering machiningof the inner conditioning surface of the porous insert may be required.

Again, the basic method of performing a post-molding conditioning of amolded article using the conditioning apparatus of the present inventionincludes the following steps, listed in sequence. Molding of a malleablemolded article 32. Configuring of a pressure structure 34 that isfluidly connected to the conditioning apparatus to function as a vacuumsource. Moving the conditioning apparatus valve member 70 into an openconfiguration to connect the conditioning cavity to the vacuum source.Transferring the molded article, in a malleable state, from the moldingcavity into the conditioning apparatus with the assistance of suctionprovided through the transfer flow structure. Moving the valve memberinto the closed configuration once a portion of the molded article hasbeen sealingly received within the conditioning cavity. Expanding anouter surface of the portion of the molded article into contact with acooled inner conditioning surface of the conditioning cavity byevacuating any air contained between the outer surface of the moldedarticle and the inner conditioning surface of the conditioning body.Maintaining a vacuum to hold the outer surface of the preform in contactwith the cooled inner conditioning surface of the conditioning cavityuntil the molded article has solidified to an extent required tomaintain its shape once ejected from the conditioning apparatus. Lastly,ejecting the molded article from the conditioning cavity.

Preferably, the method also includes the step of performing apressurized air purging of the conditioning apparatus upon ejection ofthe molded article.

Of course, the end seal 104 on any of the cooling tube assemblies 50,150, 250, 350, 450, 550, 650 of the present invention could be locatedanywhere thereon that suits the shape of the molded article 32 and theportion thereof to be conditioned. For instance, to isolate an inwardlytapered upper portion (not shown) of a preform 32 it may be necessary toconfigure the end seal 104 to be substantially on the inner conditioningsurface 61 of the cooling tube assembly. In addition, the end seal 104may need not always be made from a conformable substance, but rathercould, for instance, be configured as a flat, substantially rigid, uppersurface of the cooling tube assembly 50 for cooperation with thecorresponding flat bottom surface of the preform support ledge 86.

Alternatively, other molding system configurations are possible thatcould make use of the conditioning apparatus 50, 150, 250, 350, 450,550, 650. As an example, the cooling tube assembly 50 could beconfigured in a post-molding conditioning station that is not configuredto retrieve the molded article directly from the mold, but ratherreceives the molded article from an intermediate transfer apparatus. Theforegoing intermediate transfer apparatus may, for example, include theend-of-arm-tool that is described in commonly assigned patentpublication WO 2004/007170, published Jan. 22, 2004. As another example,the molding system may also include a blow molding machine. Furthermore,the molded article to be conditioned could also be compression molded,extrusion molded, or any other commonly known methods of molding plasticarticles.

Alternatively, while the conditioning apparatus of the present inventionare preferably configured to have a conditioning cavity thatsubstantially reflects the shape of the molded article presented to itfrom the molding machine, it is without specific limitation thereto.

Alternatively, the conditioning apparatus of the present invention couldbe configured with a plurality of porous inserts therein.

Alternatively, the conditioning apparatus of the present invention couldbe configured to include a conditioning body that comprises a pluralityof inserts that are formed from a thermally conductive material that issubstantially without an intrinsic porosity. A plurality of flowmicro-channels are configured between the inserts to provide a fluidconnection between an air pressure structure and an inner surfaceconfigured on the plurality of inserts. The micro-channels arepreferably configured on a thin spacer element that is arranged betweenadjacent inserts. Alternatively, the micro-channels could be etched ofotherwise formed on the interfacing surfaces between the adjacentinserts.

The conditioning body is provided by a insert formed from a thermallyconductive material, substantially without an intrinsic porosity, withinwhich a plurality of flow channels are machined between an insideconditioning surface and an outer surface thereof. The flow channels maybe formed using known methods such as spark erosion, and lasermicro-machining.

Thus, what has been described is a conditioning apparatus for apost-molding conditioning of molded articles that includes a suctionchannel valve member, a multi-layer porous insert, a porous insert witha coolant channel formed directly thereon, methods of making theaforementioned, and a method of using a cooling tube assembly, whichwill greatly reduce the cost of such tubes in injection molding and/orimprove the quality of molded articles, particularly preforms.

All U.S. and foreign patent documents, and articles, discussed above arehereby incorporated by reference into the

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The individual components shown in outline or designated by blocks inthe attached figures are all well-known in the injection molding arts,and their specific construction and operation are not critical to theoperation or best mode for carrying out the invention.

While the present invention has been described with respect to what ispresently considered to be the preferred embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. The scope of the following claims is to be accorded thebroadest interpretation so as to encompass all such modifications andequivalent structures and functions.

1. A method for molding an article in a molding system that includes amolding machine and a post-molding molded article conditioningapparatus, the method including the steps of: molding a molded article;configuring a pressure structure connected to said conditioningapparatus to function as a vacuum source; moving a valve member of saidconditioning apparatus into an open configuration to connect aconditioning cavity of said conditioning apparatus to said vacuum sourcethrough a transfer flow structure of said conditioning apparatus;transferring said molded article, in a malleable state, into saidconditioning cavity with the assistance of suction provided through saidtransfer flow structure; moving said valve member into a closedconfiguration once a portion of said molded article has been sealinglyreceived within said conditioning cavity; expanding an outer surface ofsaid portion of said molded article into contact with a cooled innerconditioning surface of said conditioning cavity by evacuating any aircontained between said outer surface of said molded article and saidcooled inner conditioning surface through a plurality of openingsconfigured along at least a portion of said cooled inner conditioningsurface and through to said pressure structure via a pressure couplingstructure of said conditioning apparatus; maintaining a vacuum to holdsaid outer surface of said preform in contact with said cooled innerconditioning surface of said conditioning cavity until said moldedarticle has solidified to an extent required to maintain its shape onceejected from said conditioning apparatus; ejecting said molded articlefrom said conditioning cavity.
 2. The method in accordance with claim 1,wherein said step of ejection of said molded article further includesthe step of configuring said pressure structure to function as apressure source, and thereby release said vacuum, and thereby alsoperforming a purge cleaning of said plurality of openings.